Did Supernova Explosion Contribute to Earth Mass Extinction?

A faraway supernova explosion may have contributed to a minor mass extinction here on Earth 2.59 million years ago, a new study suggests. Fast-moving, charged particles called cosmic rays that were blasted out by asupernova may have played a role in the climatic changes that apparently led to a die-off at the end of the Pliocene epoch and the start of the Pleistocene, researchers said. Around this time and afterwards, we started having glaciations — ice ages — over and over again, an